Incandescent electric lamp



(No Model.)

T. A. EDISON,

INGANDESGENT ELEUTRIG LAMP. No. 304,086. Patented Aug. 26, 1884.

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THOMAS A. EDISON, OF MENLO PARK, NEXV JERSEY.

INCANDE SCENT ELECTRlC LAMP.

FJPECIFICATION forming part of Letters Patent No. 30%,086, dated August 26, 1884;.

Application filed January 24, 1884. (No modeLl T etZZ whom, it may concern:

Be it known that I, Trronas A. EDISON, of Menlo Park, in the county of Middlcsex and State of New Jersey, have invented a new and useful Improvement in Incandescing Electric Lamps, (Case No. 609,) of which the following is a specification.

The object of this invention is to provide good electrical contact between the bottom plate of a socket or receptaeleand the tip or button on the base of an electric lamp or on a safetycatch plug or a drop-light plug, which is inserted in such socket or receptacle; and also in the case of an incandeseing electric lamp to allow the lamp to be turned in the socket to bring the filament into any desired position without breaking connection. I accomplish this by providing the lamp base or plug with a spring tending to force the two plates apart, through which sprin g the electrical connection is maintained. The two plates are thus held closely together, and a better contact is obtained than where the plates are simply placed together as heretofore. In the sockets heretofore used, when the lamp is screwed down so that the base-plates are in contact, it cannot be moved any farther. Therefore the lamp cannot be adjusted so as to bring the filament into a diiicrent position. This may produce an undesirable eii'ect, for it is of course preferable that several lamps in the same fixture should have their filaments turned so as to produce a symmetrical appearance. Then my invention is employcd,the lamp may be turned in the socket while the spring continues to maintain contact until the desired adjustment is reached.

In the accompanying drawings, Figure 1 is a view in elevation of an electric lamp employing one form of my invention; Fig. 2, a bottom view of the same or of a similarly-constructed safety-catch or other plug. Figs. 3 and 4 are elevations of plugs having other forms of springs, and Fig. 5 a bottom View of the plug shown in Fig. 4.

It is evident that each form of spring can be applied either to a lamp or to a plug.

A is the glass inclosingglobe of an incandescing electric lamp. The lamp is provided with a base, upon which are fixed a screwthreaded metal band or ring, B, and a metal cap, 0. Upon the cap 0 is attached a fiat spring, a, soldered to the cap throughout a portion of its length, while a portion of it rises from the cap, so as to form a spring.

In Fig. 3 a spiral sprin b, is soldered to the side of the cap and its other end to the bottom of a plate, 0.

In Figs. 4 and 5, the bent spring at is attached to the bottom of the cap.

In Figs. 3, l, and 5, D is a safetyeatch, droplight, or other plug, which is the equivalent of a lamp so far as this invention is concerned.

\Vhat I claim is 1. An electric-lamp base or plug of insulating material provided with a metallic screwring upon the exterior of its body and a metallic spring-tip forming the terminals of the base or plug, substantially as set forth.

2. An electric-lamp base or plug of insulat ing material provided with a metallic screw ring upon the exterior of its body, a metallic tip, and a spring secured to such'tip and forming a yielding extension thereof, substantially as set forth.

This specification signed and witnessed this th day of December, 1883.

THGS. A. EDISON. 

